Combustion chambers

ABSTRACT

The combustion chamber has a burner tube whose closed end has at least one fuel injector and whose open end emerges into a pipe leading the gaseous mixture towards its position of use. The burner tube includes a number of orifices distributed circumferentially and along axially staggered sections. An outer enclosure is arranged around the burner tube and connected in sealed manner to the open end of the said burner tube. A first pipe, supplied with oxygen-rich gas, is connected in the neighborhood of the closed end of the burner tube. A second pipe supplied with oxygen-poor gas, is connected in the neighborhood of the open end of the burner tube.

United States Patent 1 Melchoir 1 June 5,1973

[ COMBUSTION CHAMBERS [75] lnventorz- Jean Melchoir, Fontenay-aux-Roses,

France 22 Filed: June28, 1971 211 Appl.No.: 157,460

[30] Foreign Application Priority Data July 7, 1970 France ..7025074 [52] US. Cl. ..60/l3, 60/39.65, 60/303 [51] Int. Cl ..F02c 7/08 [58] Field of Search ..60/303, 307, 308, 60/317, 13, 13 N, 39.52, 39.55, 39.65;

431/5, 9,115, DIG. 3

[56] References Cited UNITED STATES PATENTS 2,168,313 8/1939 Bichowsky ..60/39.55

872,806 12/1907 Ferranti ..60/39.55

2,633,698 4/1953 Nettel ..60/13 2,669,090 2/1954 Jackson ..60/l3 3,280,555 10/1966 Charpentier et al ..60/395 Primary Examiner-Carlton R. Croyle Assistant ExaminerRobert E. Garrett Att0rney-Larson, Taylor & Hinds [57] ABSTRACT The combustion chamber has a burner tube whose closed end has at least one fuel injector and whose open end emerges into a pipe leading the gaseous mixture towards its position of use. The burner tube includes a number of orifices distributed circumferentially and along axially staggered sections. An outer enclosure is arranged around the burner tube and connected in sealed manner to the open end of the said burner tube. A first pipe, supplied with oxygen-rich gas, is connected in the neighborhood of the closed end of the burner tube. A second pipe supplied with oxygen-poor gas, is connected in the neighborhood of the open end of the burner tube.

10 Claims, 4 Drawing Figures PATENTEUJUH 5 ma saw 1 of 3 3,735, 52

a9 6o K Moe/v60 L .K ee\6 8 @V moo: m 9 3 COMBUSTION CHAMBERS The invention relates to combustion chambers supplied, on one hand, by fuel, and, on the other hand, both by gas rich in oxygen intended for ensuring the combustion and by a gas poor in oxygen intended to be mixed with the gases resulting from the combustion.

The invention relates more particularly, but not exclusively, among these combustion chambers, to those applied to the reheating of exhaust gases (gases poor in oxygen) from an internal combustion engine supercharged by a turbocompressor unit, of which the compressor supplies in parallel the said internal combustion engine and the combustion chamber (gas rich in oxygen).

In a combustion chamber of the type mentioned above, there is risk of producing instabilities during the combustion, even an arrest of combustion, when the ratio between the flow rate of oxygen-poor gas and the flow rate of oxygen-rich gas varies.

It is an object of the invention to overcome this drawback and to obtain a combustion chamber in which the combustion is stable and independent of the ratio between the oxygen-poor gas flow rate and the oxygenrich gas flow rate, it being understood that the latter remains sufficient to ensure a stoichiometric mixture or substantially stoichiometric.

The combustion chamber according to the invention includes a burner tube of which the closed end bears at least one fuel injector and of which burner tube the open end opens into a pipe leading the gaseous mixture towards its position of use, this burner tube including a certain number of orifices distributed circumferentially and along sections staggered axially, and it is characterized by the fact that an outer enclosure is arranged around the bumer tube and is connected in sealed manner to the open end of the said burner tube, said outer enclosure being supplied, on one hand, with gas rich in oxygen, by first means, in the neighborhood of said fuel injector, and, on the other hand, with gas poor in oxygen, be second means, more remote from said fuel injector.

It will then be seen that the ratio between the flow rate of the oxygen-rich gas and the flow rate of the oxygen-poor gas can vary without the organization of the combustion in the burner tube being disturbed, since there is produced in fact in the space bounded by the outer enclosure and the burner tube a zone of separation between the oxygen-rich gas and the oxygen-poor gas, this zone of separation moving when the abovesaid ratio varies.

The invention consists, apart from the main feature which has just been considered, of certain other features which are preferably used at the same time and which will be more explicitly considered below.

In order that the invention may be more fully understood, several preferred embodiments of combustion chambers according to the invention are described below purely by way of illustrative but non-limiting examples, with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic section of a combustion chamber constructed according to the invention;

FIG. 2 is a diagrammatic section of a second embodiment of a combustion chamber constructed according to the invention;

FIG. 3 shows diagrammatically a supercharged Diesel engine equipped with a combustion chamber according to a first embodiment of the invention;

FIG. 4 shows diagrammatically a supercharged'Diesel engine equipped with a combustion chamber according to a second embodiment of the invention.

The combustion chamber shown in FIGS. 1 and 2 includes a burner tube 1 whose closed end 2 bears a fuel injector 3, and whose open end 4 opens into a pipe leading the gaseous mixture towards its position of use.

In the case, shown FIGS. 3 and 4, where this combustion chamber is applied to the reheating of the exhaust gases from a Diesel engine 5 supercharged by a turbocompressor group 6, the open end 4 of the burner tube 1 opens directly into the distributor of the turbine 6a of the said turbocompressor group.

The burner tube 1 includes a certain number of orifices 7 distributed circumferentially and along sections staggered axially.

An outer enclosure 8 is arranged around the burner tube 1 and is connected in a sealed manner to the open end 4 of the said burner tube 1.

A first pipe 9 (constituting the first means) supplies, with air emerging from the compressor 6b of the turbocompressor 6, the portion of this enclosure 8 situated in the vicinity of the fuel injector 3, i.e. near the closed end 2 of the burner tube 1.

A second pipe 10 (constituting the second means) supplies, with exhaust gases emerging from the Diesel engine 5, the portion of this enclosure 8 situated more remote from the fuel injector 3, i.e. in the neighborhood of the open end 4 of the burner tube 1.

Although the outer enclosure 8 can surround the burner tube 1 at the level of its closed end 2, it seems preferable to arrange this outer enclosure 8 so that it is connected in sealed manner on the burner tube 1 at the level of its closed end 2.

In the embodiments illustrated in FIGS. 1 and 2, the first pipe 9 is connected to the outer enclosure 8 through a distributing tank 11. a

As for the second pipe 10, and according to the embodiment illustrated in FIG. 1, it is connected to the outer enclosure 8 through a distributing tank 12.

However this second pipe can also, according to the embodiment illustrated in FIG. 2, be connected to an annular enclosure 13 through a distributing tank 14,

this annular enclosure 13 surrounding the outer enclosure 8 at the level of its wall neighboring the open end 4 of the burner tube 1, orifices 15, distributed circumferentially and along sections staggered axially, being arranged in the wall of the outer enclosure 8 to ensure the passage of gases from the annular enclosure 13 to the outer enclosure 8. This arrangement enables a better distribution of the exhaust gases in the outer enclosure 8 to be obtained.

As regards the burner tube 1, it is provided, between its combustion zone In and its mixing zone lb, with axial slits 16 through which air cools the walls of the mixing zone 1b.

In the embodiment illustrated in FIG. 4, the first pipe 9 is coaxially disposed with the burner tube 1 and surrounds its closed end 2. The second pipe 10 is also coaxially disposed with the burner tube 1 and surrounds the first pipe 9, the cross-section of said second pipe being annular.

Finally, the combustion chamber constructed according to the invention is the seat of a combustion which is stable and independent of the ratio between the flow rate of combustion gas and the flow rate of air, which ratio is essentially variable in the case of a supercharged Diesel engine.

It is hence possible to calculate the flow rate of the compressor of the supercharging unit solely as a function of the Diesel engine and of the conditions of stoichiometric combustion in the combustion chamber. On the other hand, the use of a conventional combustion chamber would lead to calculating the flow rate of the compressor with a wide safety margin to ensure the combustion and, for this reason, would have increased the size, hence the price, of the supercharging unit.

I claim:

l. A power plant comprising an internal combustion engine provided with an intake manifold and an exhaust manifold, said internal combustion engine being turbo-charged by at least one compressor driven by at least one turbine and a combustion chamber comprismg:

a burner tube having a closed end provided with at least one fuel injector and an open end communicating with said turbine, said burner tube including a plurality of orifices circumferentially and axially spaced,

an outer enclosure arranged around said burner tube and connected in a sealed manner around the open end of said burner tube,

first connecting means introducing oxygen-rich gas from said compressor to a first zone of said outer enclosure in the neighborhood of said fuel injector,

and second connecting means introducing exhaust gases from said exhaust manifold to a second zone of said outer enclosure more remote from said fuel injector,

said outer enclosure defining, around said burner tube, an unobstructed annular space between said first zone and said second zone, whereby a front between said oxygen-rich gas and said exhaust gas in said outer enclosure is mobile according to their relative flow rates without disturbing the stability of combustion in the burner tube.

2. Combustion chamber according to claim 1, wherein the outer enclosure is connected in sealed manner onto the periphery of the burner tube at the level of its closed end.

3. The power plant chamber according to claim ll, wherein the first connecting means comprises a first pipe and a first distributing tank, said first pipe being connected to the outer enclosure through said distributing tank.

4. The power plant according to claim 1, wherein said second connecting means comprises a second pipe and a second distributing tank, said second pipe being connected to the outer enclosure through said distributing tank.

5. The power plant according to claim 1, wherein said second connecting means comprises a second pipe, an annular enclosure and a second distributing tank, said second pipe being connected to said annular enclosure through said distributing tank, said annular enclosure surrounding the outer enclosure at the level of its part neighboring the open end of the burner tube, orifices distributed circumferentially and along sections staggered axially being arranged in the walls of the outer enclosure to ensure the passage of the gases from the annular enclosure to the outer enclosure.

6. The power plant according to claim 1, wherein said first connecting means comprises a first pipe coaxially disposed with the burner tube and surrounding its closed end, and said second connecting means comprises a second pipe coaxially disposed with the burner tube and surrounding said first pipe.

7. The power plant. according to claim 1, wherein the burner tube includes a combustion zone towards its closed end and a mixing zone towards its open end, axial slits being provided between the said combustion zone and the said mixing zone.

8. The power plant according to claim 2, wherein said first connecting means comprises a first pipe and a first distributing tank, said first pipe being connected to the outer enclosure through said distributing tank.

9. The power plant according to claim 6, wherein the burner tube includes a combustion zone towards its closed end and a mixing zone towards its open end, axial slits being provided between the said combustion zone and the said mixing zone.

10. The power plant according to claim 1, wherein said compressor supplies air in parallel to the internal combustion engine and said combustion chamber.

saggy UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 7 6,7 52 D d June 5, 1973 I Jean Melchior It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the title page, both occurrences, please cancel "Melchoir" and insert -Melchior-- Signed and sealed this 24th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. Attesting Officer C. MARSHALL DANN Commissioner of Patents 

1. A power plant comprising an internal combustion engine provided with an intake manifold and an exhaust manifold, said internal combustion engine being turbo-charged by at least one compressor driven by at least one turbine and a combustion chamber comprising: a burner tube having a closed end provided with at least one fuel injector and an open end communicating with said turbine, said burner tube including a plurality of orifices circumferentially and axially spaced, an outer enclosure arranged around said burner tube and connected in a sealed manner around the open end of said burner tube, first connecting means introducing oxygen-rich gas from said compressor to a first zone of said outer enclosure in the neighborhood of said fuel injector, and second connecting means introducing exhaust gases from said exhaust manifold to a second zone of said outer enclosure more remote from said fuel injector, said outer enclosure defining, around said burner tube, an unobstructed annular space between said first zone and said second zone, whereby a front between said oxygen-rich gas and said exhaust gas in said outer enclosure is mobile according to their relative flow rates without disturbing the stability of combustion in the burner tube.
 2. Combustion chamber according to claim 1, wherein the outer enclosure is connected in sealed manner onto the periphery of the burner tube at the level of its closed end.
 3. The power plant chamber according to claim 1, wherein the first connecting means comprises a first pipe and a first distributing tank, said first pipe being connected to the outer enclosure through said distributing tank.
 4. The power plant according to claim 1, wherein said second connecting means comprises a second pipe and a second distributing tank, said second pipe being connected to the outer enclosure through said distributing tank.
 5. The power plant according to claim 1, wherein said second connecting means comprises a second pipe, an annular enclosure and a second distributing tank, said second pipe being connected to said annular enclosure through said distributing tank, said annular enclosure surrounding the outer enclosure at the level of its part neighboring the open end of the burner tube, orifices distributed circumferentially and along sections staggered axially being arranged in the walls of the outer enclosure to ensure the passage of the gases from the annular enclosure to the outer enclosure.
 6. The power plant according to claim 1, wherein said first connecting means comprises a first pipe coaxially disposed with the burner tube and surrounding its closed end, and said second connecting means comprises a second pipe coaxially disposed with the burner tube and surrounding said first pipe.
 7. The power plant according to claim 1, wherein the burner tube includes a combustion zone towards its closed end and a mixing zone towards its open end, axial slits being provided between the said combustion zone and the said mixing zone.
 8. The power plant according to claim 2, wherein said first connecting means comprises a first pipe and a first distributing tank, said firsT pipe being connected to the outer enclosure through said distributing tank.
 9. The power plant according to claim 6, wherein the burner tube includes a combustion zone towards its closed end and a mixing zone towards its open end, axial slits being provided between the said combustion zone and the said mixing zone.
 10. The power plant according to claim 1, wherein said compressor supplies air in parallel to the internal combustion engine and said combustion chamber. 